Modern commerce is increasingly dependent on transporting goods using carriers as society embraces more and more online shopping. For example, modern consumers are increasingly using online shopping and common carriers for delivering wine, prescription medication, food, and sensitive electronic devices. To assist in tracking and monitoring the movement of sensitive and expensive goods, labels have been developed in the past that incorporate RFID communication and intelligence. In this way, at the point of shipment and throughout the major carriers, the good has the ability to be tracked. However, adoption of such RFID labels has been slow, as the equipment for initializing, loading, updating, and interrogating the label's RFID electronics is expensive, and typically only available at larger transfer points in the shipping transaction. Further, it is unlikely, and even rare, for the end consumer to be able to interact with the label. Since the consumer is a critical part of the delivery chain, and the consumer is excluded from participation in the information available on the label, the use of intelligent labels has been quite low and very ineffective in improving the customer experience.
Intelligent labels, packaging, tags, windshield stickers, stand-alone displays and other devices, collectively referred to herein as “intelligent labels,” benefit from electro-optic devices that display messages that alert, update and inform the persons or machines proximate to them, as fully set forth in co-pending patent application Ser. No. 14/479,055, filed Sep. 5, 2014, and entitled “An Intelligent Label device and Method,” which is incorporated herein in its entirety. This earlier application describes an intelligent label that can be attached to any good, and then is used to provide a visual indicator to a human or machine on some condition or event in that distribution path. Of particular interest therefore are bistable and permanently irreversible electro-optic displays and intelligent labels that comprise them. In one example of using the intelligent label, if a good is subjected to an extreme temperature or to vibration shock, then a visual indicator may be set such that a human or a machine will understand that the good is no longer of acceptable commercial quality. Of course, it will be appreciated that machines can perceive information outside of the normal human optical range. Messages for the intelligent label are visually perceptible forms of data, information, content, text, patterns, images, shapes, symbols, codes, and colors, for example. It is important to note that these are visual systems and the messages may change one or more times over the life of the intelligent label. Further the power source that drives them may be limited or intermittent or susceptible to accidental or intentional disruption. Other components of the intelligent label may also fail or be subject to tampering. In this way, the message that is intended by the local electronics to be displayed on the intelligent label may not actually be what the user or machine perceives. Accordingly, in some applications the utility and value of intelligent labels may depend on the confidence with which the messages can be relied upon to make decisions and take actions, and further, that the actual messages perceptible at the time those decisions were made or could or should have been made, and actions were taken or could or should have been taken can be reliably and securely verified.
In one example, doctors and other healthcare professionals need to know that they will only be held accountable for decisions made and actions taken based on the information reliably available at the time. Hospitals need to know too. As do patients and insurers and everyone else with a stake in the outcome. And they also need to know that if something goes wrong, the system cannot be tampered with and of its information is trustworthy. In a specific example, a bag of blood has reached its maximum allowed time out of refrigeration, and the electronic circuitry on its attached intelligent label has instructed a message to be displayed on the bag's irreversible display that indicates that the bag of blood can no longer be used safely. In this way, the electronic messages stored within the intelligent label's processor and memory would indicate that at the correct time the visual indicator transitioned to show that the condition of the blood had changed was no longer safe. However, in some cases an electronic or logical failure may have occurred and the visual alert message was never perceptible to the nurse or doctor. To correctly assess liability for wrongly using the blood, it would be important to know precisely what was visible on the intelligent display at the time the alert should have been set.
In another example, an experimental drug may have its expiration date shortened due to a better understanding of the drug's deterioration over time. In such a case, an intelligent label may be updated remotely to remove the original expiration date, and replace the date with a new, shorter expiration date. A patient may wrongly continue to use the drug after the new expiration date, and may later claim that the new expiration date was never displayed. Accordingly, it would be important to know what, if any, change had been made on the label at the time the expiration date should have been changed. Having such a historical understanding of what was actually displayed could be critical to patient care and assigning liability. More particularly, in some cases what was actually displayed may not have communicated the intended message to the patient or care giver. For example, even if the intended message was correct, a defect in the display or display electronics may have caused an error in what was actually displayed, and therefore may have failed to communicate the intended message. More broadly, this problem occurs any time a manufacturer, distributor, or person in control of a product wants to update the information displayed to the user or consumer. Accordingly, it would be highly desirable that an intelligent label be able to determine if the intended message was perceptibly displayed at a particular time, and in some cases generate and maintain historical record of what was actually displayed for later evaluation.
It will be appreciated that different applications require different levels of confidence in the verifiability of the system. Often it is not enough to rely on an inexpensive processor having issued a command, an on/off button being switched, or a signal being sent. Particularly over time, excessive heat or cold, shock or vibration, humidity, disruption to power, component fatigue/failure, read/write/refresh errors, electrical interference, tampering etc. can all impact the integrity of a visual system and thus confidence in the ability to verify what was actually displayed, and further what was actually perceptible, at a given moment in time. In other words, it often is not enough to know what was supposed to be displayed or what may have been displayed at a different moment in time.
Conventional displays (CRTs, LEDs, most LCDs etc.) can be thought of as self-erasing. That is, such a convention display is used to display an intended message to a user. However, there is no confirmation that the message has actually been presented in a way that is visually perceptible to the machine or human. For example, many internal and external factors can affect the visual perceptive ability of the display such as power disruption, excessive heat cold or humidity, shock vibration and pressures, and shorts and faults with the electronics or logic circuits. In some cases, feedback provided with in these conventional displays may indicate that the intended message has been displayed, however these internal or external events may limit or distort what has actually been displayed to, and perceptible by, the outside world.
Messages displayed by bistable (or multi-stable state) displays such electrophoretic and certain cholesteric or nematic LCDs are to varying degrees stable without the continuous application of power. By design, they are however reversible and the displayed messages are therefore subject to accidental or intentional erasure or alteration. The displayed information therefore cannot be verified reliably visually. As used herein the term visual refers to messages, images and the like that are perceptible by both humans and machine. Certain messages however may be perceptible by machine but not perceptible by humans. For example, they may reflect light at wavelengths outside the human perceptible range (of approximately 390 to 770 nanometers). This characteristic may be exploited in a number of ways, for example to create watermarks and other messages in response to events that are machine perceptible (readable) but not perceptible by humans. The verification systems and means described herein may be utilized with such non-visual, but machine perceptible messages.
In bistable electrophoretic displays, the application of an electrical field switches the position of charged ink particles creating two visible “states” corresponding to, for example, a white and black state as seen by the viewer. The ink particles are typically compartmentalized by use of microcapsules or microcups. Each microcapsule may contain a single or several types of ink particles, e.g. each corresponding to a specific color or optical characteristic, which may have varying degrees of mobility in the suspension fluid as a function of the applied electric switching field. The suspension fluid may further have a different optical characteristic to that of the ink particles, such as, clear, colored, absorbing, etc.
In U.S. Pat. No. 6,995,550 B2, electric sensing signals corresponding to the presence of a single type ink contained in microcapsules are discussed. In one mode discussed, a complex electrode pattern containing small detection gaps must be incorporated with the signal contribution primarily coming from the detection gaps that are positioned near the center of a microcapsule. As microcapsules are typically arranged in random patterns, only ink particles from a subset of microcapsules will contribute to the sensing signal. In another mode described, the presence of the ink particles (e.g. on the viewer side of the display microcapsules) are sensed by simply applying another write signal to the electrodes, and depending on the polarity of the write signal, deduce whether the ink particles were present or not. If the probing write signal is of the same polarity as the original write signal applied to set the display state, there will be no or only a small transient current present as all or most if the ink particles are already at or near one side of the display defining the presumed state. This scheme assumes that not only the state was presumed to be the correct one, but also that the display pixel/segment is functioning correctly. However, if the latter is not the case, for instance due to some irreversible damage present (for example, a discontinuity in of the two corresponding pixel electrodes, or an undesirable chemical degradation within the microcapsule), there could also be no, or only a small (residual), transient current irrespective of the state of the display pixel/segment. In order to electrically confirm the integrity of the display pixel/segment, the opposite polarity of the probing write signal could deliberately be applied. However, this method would thus change the very display state that is to be verified electrically.
Based on the above it becomes clear that it is desirable to have electrical verification methods and systems, which utilize the same set of electrodes employed for setting the display state, and in which substantial portion of ink particles from each microcapsule or microcup within a pixel or segment contribute to the verification signal. Furthermore, it is desirable to not disturb or only minimally disturb the optical display state during the electrical signal verification process to confirm the optical display state.
Accordingly, there is a need to reliably verify that an intended message has been presented on a display in a visually perceptive manner. In some cases, the stakeholders would also benefit from generating and maintaining a historical record of what was actually perceptibly displayed on the label.